SFRP5 and hyperinsulinism: In response to hyperinsulinemia during 6-h HEC, circulating SFRP5 in 20 healthy subjects significantly dropped from 63.78 ± 20.35 pg/mL to 56.8 ± 18.46 pg/mL at 120 min (p = 0.02), then to 54.19 ± 21.73 pg/mL at 360 min (p = 0.001) (Fig. 2a).